86 vro 140 rectifier problem

[need 2 fish]

My johnson 90 degree looper vro 140 does not appear to be charging my battery. I have a self powered tach using a mag pickup at the flywheel so I cannot use it as a tell tale sign for the rectifier. Left the serial # of the motor at the house but wanted to post today so i could hopefully get some help for tonight. My old battery vibrated loose in the compartment and the positive post appears to have banged into a metal perko rod holder, I replaced the battery and will install nylock nuts tonight to reduce arcing potential. Engine cranked well on new hot battery and fished all day using baitwell and radio which was tied to my cranking battery but will now be moved to an accesory batt. left baitwell on all night(25 cent a piece shrimp are expensive) went out at 10pm and cranked engine, let it run for a while to charge but didnt look at volt meter,then woke up at 5 am to dead battery. Jumped off and notice 8 VDC, let run an no increase in voltage, raised rpm from 1000 to 2200 still no improvement. Using my fluke 87 verified on board volt meter to be correct 7.87 VDC. Ran back to launch from camp for 45 minutes with another boat monitering voltage, nada. Stator appears to be providing adequate voltage to power packs so I ASSume that is ok or I wouldnt have been able to get back to the launch. I believe the old battery arced to my rod holder blowing the diode in the rectifier???? Is the rectifier located on the starboard side of the motor on th 90 degree looper? Sorry for long post but am trying to get back on the water this weekend.

 

[dcolpitts]

Re: 86 vro 140 rectifier problem

MY 1986 140HP HAS THE RECTIFIER IN THE CENTER, BEHIND THE FLYWHEEL UNDER THE PLASTIC COVER, THAT COVERS THE TERMINAL BLOCK AND THE RECTIFIER. IT IS BELOW THE TERMINAL BLOCK, I BELIEVE THE RECTIFIER IS WATER COOLED AS WELL, GOOD LUCK

 

[need 2 fish]

Re: 86 vro 140 rectifier problem

Thanks, found it on top, behind flywheel. Brought the boat to work today and hope to sneek out and tinker with it. Are there any special precautions to take when removing a water cooled rectifier?

 

[need 2 fish]

Re: 86 vro 140 rectifier problem

while I'm here i would also like to ask about what are the best spark plugs to use and at what gap should they be at? The model # is J140TLCOG, serial # 7037040

 

[Mettaree]

Re: 86 vro 140 rectifier problem

Champ QL77JC4 30 thou. Model # indicates 1985<br /> CO = 85 INTRODUCES

 

[OBJ]

Re: 86 vro 140 rectifier problem

Need2.....You got back to the dock because once the engine starts, it's self sustaining. A separat coil under the flywheel provides the power for the power pack. So all the rectifier does is charge the battery for the next start and accessories. Just a little FYI here.

 

[need 2 fish]

Re: 86 vro 140 rectifier problem

Thanks Jim, I ASSumed my ignition portion of the system was functioning properly due to that exact occurance. I'm still at work now doing as many checks as I am capable of before I break down tomorrow and buy a new rectifier. Found some pretty good stuff through multiple searchs and believe I've found accurate test specs. Would do them all but the wife keeps caling. Let me ask ya'll this. If I dissconnect the battery leads after the motor starts and is running, would i see 13.5vdc at the cables with my Fluke meter? New battery, still did a load test just to be sure, about to check AC output to rec then amp read dc output and pray this is not my charge coil under the flywheel.

 

[OBJ]

Re: 86 vro 140 rectifier problem

Need2....ya' really don't wanna disconnect the battery with the engine running. Has a bad habit of screwing things up. To get an idea of what the recitfier is doing, put an amp meter between the rectifirer and the battery. If ya' don't show rated output at engine rpms', then 9 times outta ten the rectifier is done.

 

[need 2 fish]

Re: 86 vro 140 rectifier problem

O.K. wont try that. Thought I had a DC amp clamp here but no luck. Any idea what color the charge coil AC output wires are so I can verify it? If it's two yellows then I think I'm screwed because I only read 1.2 VAC.

 

[Bobby D.]

Re: 86 vro 140 rectifier problem

Hi need2, somewhere I read in this forum that you can use a rectifier from Radio Shack. Only a couple of bucks. Do a search or if someone is more knowledgeable than I step right in and help out the lad.

 

[seahorse5]

Re: 86 vro 140 rectifier problem

You can use the extended nose Champion sparkplug QL78YC in that looper outboard for better drivabiltiy.

 

[wilde1j]

Re: 86 vro 140 rectifier problem

If you have decent AC voltage to the rectifier AND the measured voltage across the battery terminals at idle is < 13.5 volts or more, you need a rectifier/regulator. I have an '85 140 [same block] and that's one of the few failures I've ever had with that motor.<br /><br />You need a shop manual to check and verifiy the stator output AC voltage and wire color. If I recall correctly, I think the AC supply to the rectifier needs to be ~ 50+ VAC, but I'm sure it needs to be over 20 VAC.<br />Good luck.

 

[need 2 fish]

Re: 86 vro 140 rectifier problem

Thanks to all for recomendations. Got a manual today and fooled around with it for a while, looks like my rectifier is fried bit still not sure. Will go thorugh all the troubleshooting tests once I get back from a two week service call. Almost bought one a couple of days ago just to gamble and try to be on the water this weekend. We're slaughtering the specks down here in Bayou Country.